<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box {
      height: 800px;
    }

    #b1 {
      background-color: pink;
    }

    #b2 {
      background-color: red;
    }

    #b3 {
      background-color: orange;
    }

    #b4 {
      background-color: skyblue;
    }

    .side-bar {
      position: fixed;
      top: 0;
      right: 0;
      background: white;
    }
  </style>
</head>

<body>
  <div class="side-bar">
    <a href="#b1">b1</a>
    <a href="#b2">b2</a>
    <a href="#b3">b3</a>
    <a href="#b4">b4</a>
  </div>

  <div class="box" id="b1"></div>
  <div class="box" id="b2"></div>
  <div class="box" id="b3"></div>
  <div class="box" id="b4"></div>
</body>

</html>